Investigation of the corrosion behavior and bioactivity of TI6AL4V alloy coated with bio-composite powders in simulated body fluid

This study investigates the effect of incorporating ZrO₂ and CeO₂ particles on the corrosion resistance of Ti6Al4V alloy for knee implant applications in simulated body fluid (SBF) at 37 °C. PLA-based coatings were reinforced with 9 wt.% and 15 wt.% of CeO₂ and ZrO₂ particles. alongside a control coating of 100 wt% PLA. The coatings were applied using the Electrostatic Spray Deposition (ESD) technique. Surface morphology analysis using SEM/EDS revealed the accumulation of calcium and phosphorus within the coatings, indicating enhanced bioactivity and strong bonding potential with surrounding bone tissue. Scratch hardness testing demonstrated improved adhesion and the formation of a protective layer compared to uncoated titanium alloy. Electrochemical behavior was evaluated using the potentiostatic method, including Tafel slope analysis, corrosion rate (mm/y), and polarization resistance (Rp). Results showed a significant reduction in corrosion current density and corrosion rate with the addition of ceramic particles. Notably, the corrosion rates reached 0.001552 mm/y for (PLA + 15% ZrO₂) and 1.901 × 10⁻⁶ mm/y for (PLA + 15% CeO₂), compared to 0.34109 mm/y for uncoated titanium alloy, confirming the effectiveness of the composite coatings.